Sparse drug concentration data analysis using a population approach: a valuable tool in clinical pharmacology

1. Drug concentration or pharmacological effect data collected from patients during therapy or as part of a Phase III or post-marketing study are generally sparse (i.e. one or a few observations per patient) in nature. 2. The population approach to analysing sparse drug concentration data provides a valuable tool for obtaining information about the pharmacokinetics of drugs in special patient groups (neonates, aged or critically ill), the importance of drug interactions in the clinic (using routinely collected blood concentration data) and for conducting a 'pharmacokinetic screen' in patients during early phase efficacy trials. 3. Using a population approach to analyse drug concentration-time data collected from patients during therapy or during an early phase investigation can complement information obtained from traditional pharmacokinetic/dynamic investigations to help gain a further insight into the factors that influence dosing guidelines.